Extraction of Genomic DNA - RNase A should be added during the extraction? (Jun/11/2007 )

Dear all,

I m going to extract the genomic DNA from the blood samples (I will use the Qiagen kit). Should I add RNase A to digest the RNA in the extraction? Actually, the DNA samples will be used to study the mutations or SNP of certain genes. I designed the primers which flanks the exons region only. Do you think I should use the RNA free DNA samples?

Would you give me some suggestions??

Thank you so much!

siuchi

-siuchi98-

I normally do not need the RNAse for blood sample DNA and SNP genotyping. I'd try it first without and if it doesn't work, you can add the RNase step.

-krümelmonster-

i prefer to add RNAse after extraction of the DNA and separation with the proteins, as it uses less RNases, and the RNase itself is less sensitive to proteases.

-fred_33-

QUOTE (fred_33 @ Jun 12 2007, 02:24 AM)

i prefer to add RNAse after extraction of the DNA and separation with the proteins, as it uses less RNases, and the RNase itself is less sensitive to proteases.

if i use a bit higher amount of RNase, is there any chance to degrade genomic DNA???

-T. reesei-

if the RNAse is clean from DNAses, then no harm will come by using more RNAse.

However RNAse is a protein, so what goes in must then be removed.

-perneseblue-

Agree with perneseblue. Hehe... have to clean up your sample after introducing a protein in it.